transaction.join-existing

Forces persistence context to read through JTA-managed ("write") connection in case there is an active transaction

false

(Default)

Usage

The property set in persistence.xml or passed to createEntityManagerFactory affects all EntityManagers created by the factory. If the property set to true, objects read during transaction will not be placed into the shared cache unless they have been updated. Alternatively, to apply the property only to some EntityManagers pass it to createEntityManager method.